Relativity - Aristotle, Galileo, Einstein, Einstein

[Will Bouwman]

So we all know about Galileo being banged up (placed under house arrest for purists) for arguing against the Vatican's Aristotelian stance that the Earth is the centre of the universe.

Aristotle's reasoning was based on the Greek theory of four elements, earth, water, air and fire, itself based on even older Mesopotamian and Egyptian ideas. (If you're into the really old stuff, you can read this: https://philosophynow.org/issues/104/Ph ... d_Branches) The theory being that all the elements have their natural layered place: earth at the centre, surrounded by water, air and fire all of which would eventually settle in that order; but there is also the aether above which spins around in concentric spheres, which rub against each other causing friction and thereby creating the illusion of heavenly bodies ‘particularly in that part where the sun is attached to it.’ Aristotle Metaphysics That movement is transferred down to Earth which is why everything is so mixed up.

Aristotle supported his view of a stationary Earth with the claim that if the Earth was moving, then if you dropped a stone, the stone would land as far from your feet as the Earth had moved in the time it took the stone to drop.

The idea of the Earth being at the centre of the universe, and hence the focus of God's attention, suited the Vatican and while a lot has been written about the details, the long and short of it is that the decision was made that Galileo, and his advocacy of the Copernican model of Earth in orbit around the Sun was too dangerous to be let out of the house. It didn't help that in his Dialogue Concerning the Two Chief World Systems, (Copernican and Aristotelian) the Aristotelian advocate is called Simplicio.

Anyway, in the same book Galileo countered Aristotle's claim about falling stones with this:
“Shut yourself up with some friend in the main cabin below decks on some large ship, and have with you there some flies, butterflies, and other small flying animals. Have a large bowl of water with some fish in it; hang up a bottle that empties drop by drop into a wide vessel beneath it. With the ship standing still, observe carefully how the little animals fly with equal speed to all sides of the cabin. The fish swim indifferently in all directions; the drops fall into the vessel beneath; and, in throwing something to your friend, you need to throw it no more strongly in one direction than another, the distances being equal; jumping with your feet together, you pass equal spaces in every direction. When you have observed all these things carefully (though doubtless when the ship is standing still everything must happen in this way), have the ship proceed with any speed you like, so long as the motion is uniform and not fluctuating this way and that. You will discover not the least change in all the effects named, nor could you tell from any of them whether the ship was moving or standing still.”
What he is describing is an inertial frame of reference, in which everything is moving at the same velocity relative to some external reference.


So Galilean relativity states that inside an inertial frame of reference, there is no way to know whether you are moving or not; it is only by looking out the window that you can tell you are moving relative to something else. Or it is moving relative to you - makes no difference.


The story goes that Einstein wondered what would happen if you could travel at the speed of light. Specifically he imagined looking at himself in a mirror in front of him, which, at the speed of light would go blank, because the light from his face couldn't go fast enough to reach the mirror to be reflected. This would break Galilean relativity, because there would be a way to know you are moving, albeit at the speed of light, in an inertial frame.

Einstein being Einstein decided to explore alternatives to a blank mirror and his solution was that, yeah, the mirror blanks out, but you wouldn't notice because for you, time stops. That's not some weird metaphysical spookiness, it is simply the fact that if in an inertial frame everything is moving as fast as anything can move, there can be no interaction between them - literally nothing happens. Outside the world keeps spinning and time moves on.

However, as Galileo noted, that is true only in the special case of motion that is "uniform and not fluctuating this way and that", hence special relativity. Assuming there are no flatearthers here by mistake, we all know that as we move across its surface, the Earth is spinning as it orbits the Sun, in a galaxy that is cartwheeling through a universe that is expanding. In other words, we are definitely not moving in a way that is uniform and not fluctuating this way and that, and yet relativity still holds.

General relativity deals with frames of reference which are either changing direction, changing speed or both, which is every frame of reference. Einstein claimed that being in a lift that is in free fall is equivalent to being in a lift in outer space, where there is no gravity. Here on Earth if you drop a stone, it accelerates at 9.8m per second per second. So after two seconds of falling a stone is going at 19.6m per second, after three seconds its 29.4m/s, about 100kph, 60mph. To experience the same 'gravity' a lift in outer space has to accelerate at 9.8 m/s2, or it has to change direction appropriately, which is the idea behind spinning big wheel space ships creating artificial gravity.

One of the key differences between special and general relativity is that in special relativity, there in no way to tell who is moving relative to what. Einstein illustrated this by imagining a 'light clock'. All clocks count periodic events, be that the swing of a pendulum or absorption and emission of photons in atoms. Einstein's light clock counts the bounces of a pulse of light between two mirrors facing each other stacked vertically.

According to special relativity, an observer in an inertial frame of reference (in the example Einstein used a train carriage) that includes a light clock, will see the pulse of light bouncing straight up and down. Someone else, watching the train go by, will see the light pulse take a diagonal route, because as the light leaves one mirror the other is moving and the light has to follow whatever path necessary to bounce off it. So because the speed of light is constant, the outside observer sees the clock on the train ticking slower than anyone in the carriage.

The confusing thing is that if the outside observer also has a light clock, people in the carriage see that as ticking slow. Since special relativity is about uniform velocity, the train and the outside observer will get further and further apart and never find out which clock was actually ticking slower. In general relativity, you can think of the train as being on a circular track, with the outside observer being in the middle watching the train go round and round. In that case, as I'm sure you have already realised, while the outside observer still sees the light on the train moving diagonally, anyone on the train sees the light in the middle bouncing straight up and down. In effect, that's what the Hafele-Keating experiment observed.
Anyway, as Einstein predicted, the effect on time of gravity is exactly the same as acceleration, ie, changing speed or direction. So Einstein came up with his idea of 'spacetime' being a 'fabric' that is warped by mass to account for this change of direction. But, as noted elsewhere, there are alternative explanations.

[Flannel Jesus]

People usually find it more pleasant to read words when they're split into sensible paragraphs.

I actually think you tried to do this but the paragraph splits are a bit too subtle. Maybe you need another line between paragraphs or something. The other option is to indent the first line of a new paragraph, but that doesn't really work easily here.

[Will Bouwman]

Better?

[Flannel Jesus]

Better?

Massively, I really appreciate it - and I'm sure many other readers do. Thanks.

[Impenitent]

the universe is polluted with gravitational bodies of all sorts in constant motion...

in "pure" space (completely untouched by gravitational pulls of any kind) light behaves a certain way...

I don't think there exists such a "pure" space

do bodies of any denseness exact a gravitational pull in "pure" space? infinitesimally small perhaps, I don't know...

is the observer bodiless? would the curvature of space be subject to each and every occurrence of said denseness?

with every satellite launched from Earth, the amounts of "artificial" mass change said curvature...

if light "bends" or slows in certain gravity- how is time changed?

I am still unsure if mass of any kind (creating its own gravitational pull) could move at the speed of light (especially since the speed of light cannot be constant for no "pure" space can actually be measured...)

thanks for posting, it brings up some fun questions...

-Imp

p.s. the bodiless observer observes via an ocean of light... if the observer is moving as quickly as the field of visibility itself, what exactly will be seen? will that which is within be visible or will it not be capable of being seen? turn out the light and nothing is seen... if moving as fast as light nothing will be illuminated so wouldn't that have the same effect as turning the lights out? when the light catches up to your eyes are you seeing the past?

[Will Bouwman]

the universe is polluted with gravitational bodies of all sorts in constant motion...

That's one way of putting it.

in "pure" space (completely untouched by gravitational pulls of any kind) light behaves a certain way...

Well, that's the idealised vacuum posited in Maxwell's equations, according to which light travels at 186 000 miles per second, in a straight line. It's the sort of thing that can exist in mathematics, but not, as far as we can see, in reality.

I don't think there exists such a "pure" space

In the sense you describe above, me neither.

do bodies of any denseness exact a gravitational pull in "pure" space? infinitesimally small perhaps, I don't know...

Not if pure space is a vacuum, but there are good reasons to think it isn't; rather it is an arena in which particles are constantly popping in and out of existence, which like all particles with mass, are subject to gravity.

is the observer bodiless? would the curvature of space be subject to each and every occurrence of said denseness?

The denseness isn't really the issue. Black holes are very dense; one with the mass of the Sun would be about 4 miles wide (technically that's based on the Schwartzschild radius, the black hole is even smaller), but has the same strength gravitational field strength.

with every satellite launched from Earth, the amounts of "artificial" mass change said curvature...

Well, bear in mind that even satellites are made of material dug out of the Earth, so while there is a slight redistribution, the overall gravitational strength, beyond the orbit of the satellite, isn't affected. The effect on the Earth is rather less than a mosquito lifting off from an oil tanker.

if light "bends" or slows in certain gravity- how is time changed?

Because it's not just light that slows; it is everything, so every interaction takes longer. One way to think of gravity is as refraction. Long story; you can check it out here: https://willybouwman.blogspot.com/2024/ ... ation.html

I am still unsure if mass of any kind (creating its own gravitational pull) could move at the speed of light (especially since the speed of light cannot be constant for no "pure" space can actually be measured...)

Well, yes everything that light can pass through has a refractive index, which is an indicator of how much that medium slows light down, including 'empty' space, but nothing with mass can travel at the speed of light. Water provides a loose analogy. Suppose the speed of waves is constant (it's not, but never mind, it isn't for light either). A wave travels at that speed, as light travels at the speed of light. Imagine then a whirlpool, effectively a spinning wave and an analogue of a particle. That can never travel at the speed of waves, because that would require it spinning faster than the speed of waves.

thanks for posting, it brings up some fun questions...

-Imp

And so far, none of the nutjobs.

p.s. the bodiless observer observes via an ocean of light... if the observer is moving as quickly as the field of visibility itself, what exactly will be seen? will that which is within be visible or will it not be capable of being seen? turn out the light and nothing is seen... if moving as fast as light nothing will be illuminated so wouldn't that have the same effect as turning the lights out? when the light catches up to your eyes are you seeing the past?

Don't really know what a bodiless observer would be, but I'm fairly certain that travelling at the speed of light would be fatal to anything with a body. Sorry to spoil the fun.

[Impenitent]

thanks for the explanation and the link...

-Imp

[Age]

So we all know about Galileo being banged up (placed under house arrest for purists) for arguing against the Vatican's Aristotelian stance that the Earth is the centre of the universe.

Aristotle's reasoning was based on the Greek theory of four elements, earth, water, air and fire, itself based on even older Mesopotamian and Egyptian ideas. (If you're into the really old stuff, you can read this: https://philosophynow.org/issues/104/Ph ... d_Branches) The theory being that all the elements have their natural layered place: earth at the centre, surrounded by water, air and fire all of which would eventually settle in that order; but there is also the aether above which spins around in concentric spheres, which rub against each other causing friction and thereby creating the illusion of heavenly bodies ‘particularly in that part where the sun is attached to it.’ Aristotle Metaphysics That movement is transferred down to Earth which is why everything is so mixed up.

Aristotle supported his view of a stationary Earth with the claim that if the Earth was moving, then if you dropped a stone, the stone would land as far from your feet as the Earth had moved in the time it took the stone to drop.

The idea of the Earth being at the centre of the universe, and hence the focus of God's attention, suited the Vatican and while a lot has been written about the details, the long and short of it is that the decision was made that Galileo, and his advocacy of the Copernican model of Earth in orbit around the Sun was too dangerous to be let out of the house. It didn't help that in his Dialogue Concerning the Two Chief World Systems, (Copernican and Aristotelian) the Aristotelian advocate is called Simplicio.

Anyway, in the same book Galileo countered Aristotle's claim about falling stones with this:
“Shut yourself up with some friend in the main cabin below decks on some large ship, and have with you there some flies, butterflies, and other small flying animals. Have a large bowl of water with some fish in it; hang up a bottle that empties drop by drop into a wide vessel beneath it. With the ship standing still, observe carefully how the little animals fly with equal speed to all sides of the cabin. The fish swim indifferently in all directions; the drops fall into the vessel beneath; and, in throwing something to your friend, you need to throw it no more strongly in one direction than another, the distances being equal; jumping with your feet together, you pass equal spaces in every direction. When you have observed all these things carefully (though doubtless when the ship is standing still everything must happen in this way), have the ship proceed with any speed you like, so long as the motion is uniform and not fluctuating this way and that. You will discover not the least change in all the effects named, nor could you tell from any of them whether the ship was moving or standing still.”
What he is describing is an inertial frame of reference, in which everything is moving at the same velocity relative to some external reference.


So Galilean relativity states that inside an inertial frame of reference, there is no way to know whether you are moving or not; it is only by looking out the window that you can tell you are moving relative to something else. Or it is moving relative to you - makes no difference.


The story goes that Einstein wondered what would happen if you could travel at the speed of light. Specifically he imagined looking at himself in a mirror in front of him, which, at the speed of light would go blank,

Is this actually an already proved Fact, or is this just what is 'imagined', only?

because the light from his face couldn't go fast enough to reach the mirror to be reflected.

But, if 'that body' and 'that mirror' are going as fast as the 'speed of light', then those two former things would be going at the same speed as 'the reflection'. So, the light from 'that face' would be going fast enough to reach the mirror, 'to be reflected'. Therefore, the 'image of the face' would be on, or at, 'the mirror'.

Once this is agreed with, then 'we' can move along here. Or, if one wants to disagree with this, then 'why', exactly?

This would break Galilean relativity, because there would be a way to know you are moving, albeit at the speed of light, in an inertial frame.

Is this actually an already proved Fact, or is this just what is 'imagined', only?

Einstein being Einstein decided to explore alternatives to a blank mirror and his solution was that, yeah, the mirror blanks out, but you wouldn't notice because for you, time stops.

Anyone, being anyone, would have to define the word 'time', Accurately, and exactly, before they could make the claim that 'time, itself, stops'.

Did "albert einstein", being what it is, or was, exactly, (which is, exactly, no different from what any of you other human beings are, exactly), define what 'time' is, exactly, before "albert einstein" claimed that 'time, itself, stops'?

That's not some weird metaphysical spookiness, it is simply the fact that if in an inertial frame everything is moving as fast as anything can move,

Is it an actual already proved Fact that that there is no thing that can move faster than the 'speed of light', or is this just what is 'imagined'?

After all you human beings for centuries, hitherto when this was being written, have 'imagined' that a lot of things could not go 'as fast' as they actually could end up going.

there can be no interaction between them - literally nothing happens.

Are you absolutely, without doubt, 100% sure that this is not some so-called 'weird metaphysical spookiness', which was, or is, still for some, just what is 'imagined' only?

In other words have you obtained the actual irrefutable proof for your claim/s here?

Outside the world keeps spinning and time moves on.

1. Outside of 'what', exactly?

2. What is 'the world', exactly?

3. Which, supposedly, 'keeps spinning'?

4. And, is whatever 'the world' words are referring to 'spinning' around something else, or just 'spinning', itself?

5. What, exactly, is 'time'?

6. And, how, exactly, does 'time', itself, actually 'move on'?

However, as Galileo noted, that is true only in the special case of motion that is "uniform and not fluctuating this way and that", hence special relativity. Assuming there are no flatearthers here by mistake, we all know that as we move across its surface, the Earth is spinning as it orbits the Sun, in a galaxy that is cartwheeling through a universe that is expanding. In other words, we are definitely not moving in a way that is uniform and not fluctuating this way and that, and yet relativity still holds.

Why, exactly, do you propose and claim here that you human beings are definitely not moving in a way that is 'uniform'?

General relativity deals with frames of reference which are either changing direction, changing speed or both, which is every frame of reference.

Is the 'speed of light' a 'frame of reference' that is either changing direction, changing speed, or both?

Also, for as long as there is no change in direction, nor any change in speed, then this could apply and/or occur in any 'frame of reference'. So, why do you say and claim that 'every frame of reference' there is either a change in direction or a change in speed?

Are you thinking 'eventually' here?

Or is there some other reason for your claim and/or belief here?

Einstein claimed that being in a lift that is in free fall is equivalent to being in a lift in outer space, where there is no gravity. Here on Earth if you drop a stone, it accelerates at 9.8m per second per second. So after two seconds of falling a stone is going at 19.6m per second, after three seconds its 29.4m/s, about 100kph, 60mph. To experience the same 'gravity' a lift in outer space has to accelerate at 9.8 m/s2, or it has to change direction appropriately, which is the idea behind spinning big wheel space ships creating artificial gravity.

One of the key differences between special and general relativity is that in special relativity, there in no way to tell who is moving relative to what. Einstein illustrated this by imagining a 'light clock'. All clocks count periodic events, be that the swing of a pendulum or absorption and emission of photons in atoms.

But clocks do not count periodic events. Clocks are the measuring tool to count the duration between perceived events.

Einstein's light clock counts the bounces of a pulse of light between two mirrors facing each other stacked vertically.

According to special relativity, an observer in an inertial frame of reference (in the example Einstein used a train carriage) that includes a light clock, will see the pulse of light bouncing straight up and down. Someone else, watching the train go by, will see the light pulse take a diagonal route, because as the light leaves one mirror the other is moving and the light has to follow whatever path necessary to bounce off it. So because the speed of light is constant, the outside observer sees the clock on the train ticking slower than anyone in the carriage.

Has this been shown to be a Fact, or just what is imagined to happen and/or occur?

Also, could an observation, combined with a presumption or a pre-existing belief, provide a False conclusion?

Furthermore, do the outside of the train observer/s have to see the clock on the train so-call 'ticking slower' than anyone in the carriage, or is it possible for these observers to just 'see' things 'differently' here, instead?

The confusing thing is that if the outside observer also has a light clock, people in the carriage see that as ticking slow.

Do they 'actually' see that as so-called 'ticking slow', or have they just not calibrated 'their own observation' relative to where they are and what is actually happening and occurring?

Since special relativity is about uniform velocity, the train and the outside observer will get further and further apart and never find out which clock was actually ticking slower.

But, with 'hindsight' it is very simple and very easy to realize, and thus come-to-know, that 'the light clock' will so-call 'tick' at the 'same speed, always.

If any of 'these observers' had already learned and realized that absolutely every thing is relative, to 'the observer', then this helps, tremendously, in separating what are irrefutable Facts, from what are not.

Like for example 'the clock' was never 'ticking' slower nor faster ever. It is just you human beings who 'see', or observe, things 'differently'.

In general relativity, you can think of the train as being on a circular track, with the outside observer being in the middle watching the train go round and round. In that case, as I'm sure you have already realised, while the outside observer still sees the light on the train moving diagonally, anyone on the train sees the light in the middle bouncing straight up and down. In effect, that's what the Hafele-Keating experiment observed.

'We' have, somewhat, discussed this previously. And, what 'that experiment' showed aligned far more with what I have said and claimed here, than it has with what you and others say and claim.

As I pointed out and showed to you previously, the results from that experiment countered what is claimed in those just 'theories of relativity'.

Anyway, as Einstein predicted, the effect on time of gravity is exactly the same as acceleration, ie, changing speed or direction.

But, 'time', itself, is not some thing that could be affected by gravity, acceleration, that is; speed nor direction.

But, then again, I have provided a definition for the word 'time', whereas you people, still, have not yet.

So Einstein came up with his idea of 'spacetime' being a 'fabric' that is warped by mass to account for this change of direction.

To account for what 'change of direction', exactly?

Again, is this 'fabric' a proved Fact, or just another thing 'imagined'?

But, as noted elsewhere, there are alternative explanations.

[Age]

the universe is polluted with gravitational bodies of all sorts in constant motion...

Is 'polluted' really the 'Right word' here?

That within the Universe, Itself, there is 'matter', or 'bodies', in constant motion, is something all could agree with.

in "pure" space (completely untouched by gravitational pulls of any kind) light behaves a certain way...

In 'what way' is that 'certain way', exactly?

I don't think there exists such a "pure" space

So, you also do not think that light behaves 'a certain way' either, right?

Also, why even say and write, 'in pure space', if you do not think that there even exists such a thing?

do bodies of any denseness exact a gravitational pull in "pure" space?

If there are areas of the Universe where 'matter' is not causing or creating a 'gravitational effect', or what some might call 'areas of pure space', or if there are none, might take some time to work out for 100% sure, given the actual size of the Universe, Itself. But, then again, maybe the answer to this has already been found, and thus discovered.

Is there anywhere, hitherto, in 'scientific literature' that has confirmed that there are 'areas of the Universe' where there is no 'gravitational effect'?

infinitesimally small perhaps, I don't know...

Okay.

is the observer bodiless?

In a sense, Yes. But, do not forget that it is only because of 'bodies' that 'the Observer', exists, and 'you observers', came-to-exist.

would the curvature of space be subject to each and every occurrence of said denseness?

Is it a proved Fact that 'space', itself, is curved?

And, what is the definition of the word 'space', exactly?

with every satellite launched from Earth, the amounts of "artificial" mass change said curvature...

Are you here asking, 'Does the amount of so-called 'artificial mass' changed said, claimed, curvature?

Or, are you telling 'us' that the so-called 'artificial mass' changes 'said curvature'?

if light "bends" or slows in certain gravity- how is time changed?

GREAT clarifying question here?

Hopefully, people will define what the word 'time' means first, before they answer, and clarify, here for you.

I am still unsure if mass of any kind (creating its own gravitational pull) could move at the speed of light (especially since the speed of light cannot be constant for no "pure" space can actually be measured...)

I think you will find, in the days when this is being written, that a lot of 'those' in the 'scientific community/church/religion' will tell you that it is an absolute impossibility for any thing of matter, or 'mass of any kind', to travel at the speed of light, or faster. But, if not lots, then some.

thanks for posting, it brings up some fun questions...

-Imp

p.s. the bodiless observer observes via an ocean of light...

What do you mean by 'an ocean of light'?

if the observer is moving as quickly as the field of visibility itself,

But, is the, actual, 'field of visibility, itself', of the 'bodiless Observer', any thing less than 'infinite'?

Only the 'visibility' of 'bodies' have a 'limit', or 'a field of visibility'. This is, if you are using the term or phrase, 'field of visibility, itself', in relation to the 'speed of light', itself.

what exactly will be seen?

'Objects' will appear quicker than 'expected', and, even instantaneously. While 'information/knowledge' can, and will, appear quicker than 'expected', and almost instantaneously, but never instantaneously.

(I use the 'expected' word here very 'loosely'.)

But, 'now', 'we' are, really, getting, so-called, 'deep' here. Which is Truly fantastic and what I have been Truly waiting for.

will that which is within be visible or will it not be capable of being seen?

It could be said, and argued, that 'that, which is within, is 'visible', in the sense of 'seen', in the sense of 'understood'. Which, all of, can be 'seen/understood'.

turn out the light and nothing is seen...

With and from the 'physical eyes' only.

But, lots is, still, 'seen/understood', from the other four senses of the human body. After all those bodies where the physical sense of sight does not work does not mean that ' nothing is 'seen' ', at all, to those human beings. In fact, 'they' can sometimes 'see', and 'understand', things that 'the rest' can not.

if moving as fast as light nothing will be illuminated

But, if moving as fast light, this does not then mean that nothing will be illuminated at all. Because 'light', itself, does not just move in one direction only. For example, if 'an observer' was traveling at the speed of light towards a sun, then the light from that sun is coming towards 'that one'. Maybe just faster than what was 'expected' or what one was 'used to'. Therefore, that sun will always remain illuminated.

so wouldn't that have the same effect as turning the lights out?

No, as just explained.

I was also thinking this, when I read about "albert einstein" imagining a blank mirror.

So, I will now suggest to not let another's imaginings effect how 'you' 'look at' and 'see' things. That is; if you always remain completely open, and honest, then you will, always, 'see' things for how they really are.

Now, of course, other human being's views, beliefs, imagines, thoughts, et cetera will 'influence' 'you', but if 'you' never let them effect 'the way' you 'look at' and 'see' things, then ALL will become crystal clear.

when the light catches up to your eyes are you seeing the past?

Absolutely every time when the light 'catches up', to you, then you are 'seeing' into, or from, what is called 'the past'.

[Will Bouwman]

I knew it couldn't last.

[Age]

I knew it couldn't last.

While some will notice that you, still, cannot refute, elaborate, counter, nor clarify.

[Age]

the universe is polluted with gravitational bodies of all sorts in constant motion...

That's one way of putting it.

in "pure" space (completely untouched by gravitational pulls of any kind) light behaves a certain way...

Well, that's the idealised vacuum posited in Maxwell's equations, according to which light travels at 186 000 miles per second, in a straight line. It's the sort of thing that can exist in mathematics, but not, as far as we can see, in reality.

What do you mean by 'reality'?

And, why can you, and some others, supposedly, 'not see' light just travel in a straight line?

For example, when you 'see' 'the light' from 'the sun', then how many twists and turns does it make before it reaches the eyes of 'that body'?

And, how come you can, supposedly, 'see' the twists, turns, and curves of 'light' but you, supposedly, cannot 'see' a straight line of 'light'?

I don't think there exists such a "pure" space

In the sense you describe above, me neither.

Why do you two think that there is not one area of the whole Universe where there might not be a 'gravitational effect'?

Also, would it be not just better, more helpful, and/or even just more wise, to just remain completely open, instead, until you just found out, for sure?

do bodies of any denseness exact a gravitational pull in "pure" space? infinitesimally small perhaps, I don't know...

Not if pure space is a vacuum, but there are good reasons to think it isn't; rather it is an arena in which particles are constantly popping in and out of existence, which like all particles with mass, are subject to gravity.

Is it an already proved Fact that matter, or particles, are constantly popping in and out of existence, or just what is imagined to happen and occur?

is the observer bodiless? would the curvature of space be subject to each and every occurrence of said denseness?

The denseness isn't really the issue. Black holes are very dense; one with the mass of the Sun would be about 4 miles wide (technically that's based on the Schwartzschild radius, the black hole is even smaller), but has the same strength gravitational field strength.

But, was this, more or less, not what "impenitent" was asking? That is; would the 'assumed curvature of space, itself', (whatever that actually means or is referring to, exactly), be related to the 'denseness' of 'the object'?

After all it is claimed that 'gravity bends light', which implies 'a curvature', 'somewhere', and, because 'curvature', or 'the bending of light', is said to come from 'gravity', and, 'gravity is caused by the 'denseness' of 'an object', then, if a 'black hole' could be classed as 'an object' also, because they also have a 'denseness', then, how I read was being asked here, and please Correct me if I am Wrong here "impenitent", but you are, more or less, just asking, would the amount of 'denseness of an object' effect the 'curvature of the space', around it?

Also, I am not sure it was the best idea of quoting the, 'Is the observer bodiless' as well, in the exact same quote, but then only answering/replying to one question only.

with every satellite launched from Earth, the amounts of "artificial" mass change said curvature...

Well, bear in mind that even satellites are made of material dug out of the Earth, so while there is a slight redistribution, the overall gravitational strength, beyond the orbit of the satellite, isn't affected.

This could be said for absolutely every piece of matter, or object. The gravitational strength for all 'matter' no what its size, diminishes completely beyond a certain point/orbit.

The effect on the Earth is rather less than a mosquito lifting off from an oil tanker.

if light "bends" or slows in certain gravity- how is time changed?

Because it's not just light that slows; it is everything, so every interaction takes longer. One way to think of gravity is as refraction. Long story; you can check it out here: https://willybouwman.blogspot.com/2024/ ... ation.html

At least one promotional ad was able to be achieved here.

I notice 'you', still, Wrongly call, 'the Universe', 'our universe'.

The fundamental way that the Universe actually works, and is made up of, exactly, can be and is being expressed in a, very simple, language comprehensible to every one. One just needs to express only the Truth alone for this to happen and occur. Saying things like 'our universe' is not the Truth of things. And, another prime example, of why it took human beings so, so long to comprehend what the Universe is, fundamentally, made up of and how the Universe, actually, works.

Continually re-repeating theories, assumptions, or guesses about how the Universe 'might work', and worse still expressing them as though they are actually true, right, accurate, and/or correct never helps at all. And, in fact is only slowing things down further here.

Look "will bouwman", you can keep trying to promote your book/s here. But, once more, I will suggest that if absolutely any one comes into a philosophy forum, of all places, making claims, and/or positing things, then expect to be questioned and/or challenged over those claims or positions. I also suggest having the actual proof first, for one's claims or positions, before absolutely any claim or position at all is made or put forward.

Also, your exaggerations of things do not help you express actual Facts in a language that will be comprehended Accurately. Again, you are only hindering the process of clear and absolute Correct communication by doing this.

I am still unsure if mass of any kind (creating its own gravitational pull) could move at the speed of light (especially since the speed of light cannot be constant for no "pure" space can actually be measured...)

Well, yes everything that light can pass through has a refractive index, which is an indicator of how much that medium slows light down, including 'empty' space, but nothing with mass can travel at the speed of light.

1. Why do you say things, as though they are irrefutable, or already proved True, when they are not?

2. Why did you say, 'including 'empty' space', when you were talking about light slowing down?

3. If there is matter absolutely everywhere, so-called 'popping in and out of existence', then a direct line of sight to the sun would mean that light is slowed down, somewhat, by the time is reaches 'an observer' on earth. So, my question is; is the time light takes to reach earth measured in relation to the 'speed of light' as though 'the speed of light' had not been 'slowed down', or by 'the speed of light' after it has been 'slowed down'?

And, if it is the latter, then what is the 'actual speed of light'?

Water provides a loose analogy. Suppose the speed of waves is constant (it's not, but never mind, it isn't for light either). A wave travels at that speed, as light travels at the speed of light. Imagine then a whirlpool, effectively a spinning wave and an analogue of a particle. That can never travel at the speed of waves, because that would require it spinning faster than the speed of waves.

But, this would have to be 'supposed', with an already pre-existing view or belief that traveling faster than the speed of waves was an already proved irrefutable Fact.

thanks for posting, it brings up some fun questions...

-Imp

And so far, none of the nutjobs.[/quote]

Is the word 'nutjob' here in reference to those who just challenge you by asking you questions that you cannot answer, or, who just point out some of the inconsistencies and/or contradictions in 'your, made up, stories'?

Or, if that word is in reference to some others, then would you be kind enough to be open and honest here about who and/or what 'they' are, to you?

p.s. the bodiless observer observes via an ocean of light... if the observer is moving as quickly as the field of visibility itself, what exactly will be seen? will that which is within be visible or will it not be capable of being seen? turn out the light and nothing is seen... if moving as fast as light nothing will be illuminated so wouldn't that have the same effect as turning the lights out? when the light catches up to your eyes are you seeing the past?

Don't really know what a bodiless observer would be, but I'm fairly certain that travelling at the speed of light would be fatal to anything with a body. Sorry to spoil the fun.

It was you "will bouwman", in your opening post here, who talked about one imagining if they were traveling at the speed of light. Yet, when another does the 'exact same thing', in a question to you, you want to say that doing such a thing would 'spoil the fun'. It appears that when "Albert Einstein" does this, then it is perfectly fine and okay. But, when others do this, you want to tell them that it is absolutely without any doubt at all 100% an impossible thing to do.

you were only asked about 'if', and "Impenitent" even went on to talk about a 'bodiless observer' also. Which makes you flat out ignoring the questions asked and posed to you, in a thread that you started, even more wrong.

[Will Bouwman]

Well, yes everything that light can pass through has a refractive index, which is an indicator of how much that medium slows light down, including 'empty' space, but nothing with mass can travel at the speed of light.

1. Why do you say things, as though they are irrefutable, or already proved True, when they are not?

Well, as I have said enough times for you to have noticed, nothing about the world of our perception is irrefutable, or already proven true. The only thing we can say about our perceptions that is irrefutable is that those perceptions exists. There are now, and always will be, different ways to interpret our perceptions. Anyone who cannot understand that isn't very bright. Anyone who cannot understand that and insists their interpretation is the truth is a nutjob.
If the only thing you read of that presentation is the title, The Ealing Interpretation should alert you to the fact that I am not presenting any of it as irrefutable.

[Age]

Well, yes everything that light can pass through has a refractive index, which is an indicator of how much that medium slows light down, including 'empty' space, but nothing with mass can travel at the speed of light.

1. Why do you say things, as though they are irrefutable, or already proved True, when they are not?

Well, as I have said enough times for you to have noticed, nothing about the world of our perception is irrefutable, or already proven true.

Which was my very point, and what I asked you, 'Why do you say things, as though they are irrefutable, or already proved True, when they are not?

If, to you, there is absolutely nothing at all about the world of your human being perception that is irrefutable, nor already proven true, then why do you contradict this by saying and claiming things, as though are irrefutably true, or has already been proven true?

The only thing we can say about our perceptions that is irrefutable is that those perceptions exists.

Great. Now if you just spoke and write 'like this', then I would stop pointing out your hypocrisy here.

There are now, and always will be, different ways to interpret our perceptions. Anyone who cannot understand that isn't very bright.

Well it is 'you' "will bouwman" who speaks and writes here as though you, still, have not yet fully comprehended and understood this.

Anyone who cannot understand that and insists their interpretation is the truth is a nutjob.

So, 'you' are calling "your" 'self' a "nutjob" here.

you keep speaking, writing, and insisting here that 'yours' and other's interpretations here are the truth, and worse still are the only truth.

If the only thing you read of that presentation is the title, The Ealing Interpretation should alert you to the fact that I am not presenting any of it as irrefutable.

So, once again, why speak and write as though what you say and write is irrefutable?

When , and if, you start becoming open and honest here and start answering this clarifying question instead of just keep trying to deny that this is what you are doing here, then the quicker you will see how to change for the better. Which will then, obviously, make your story writing here much more Accurate and Correct.

[Will Bouwman]

you keep speaking, writing, and insisting here that 'yours' and other's interpretations here are the truth, and worse still are the only truth.

No Age, I keep writing about underdetermination. I say again and again that there are always different ways to interpret the same data. You are the one who thinks he knows the truth.